As a general-purpose adhesive tape, for example, a product colored black has been widely used for design qualities and light blocking effects.
As a technique for black coloring, a method of mixing a coloring agent, such as carbon black, in an adhesive component has been commonly employed. This method is such that an adhesive is dissolved in a solvent, then, a coloring agent is added thereto, and applied to a base material and heated to volatilize the solvent, whereby a film is formed, and this method is applied to a method for producing what is called a solvent-type adhesive tape.
However, in a production method by which a monomer is applied to a base material and then irradiated by an active energy ray, whereby the monomer is polymerized to be made into an adhesive, sometimes the active energy ray is shielded or absorbed by a coloring agent such as carbon black, whereby the active energy ray is inhibited from reaching the monomer and a polymerization initiator. Furthermore, sometimes, a functional group, such as a hydroxyl group or a carboxyl group, which is present in the surface of carbon black or the like deactivates a reaction growth site formed by an active energy ray, whereby a polymerization reaction of the monomer is inhibited.
Patent document 1 discloses that colored plastic beads are employed for a pressure-sensitive adhesive layer which is produced by polymerizing a monomer by an active energy ray, but, with a technique disclosed in Patent document 1, it is difficult to achieve excellent chromaticity and a sufficient degree of cure.